The invention concerns preparations for the external application of agents with antiseptic and/or wound healing promoting properties. The preparations are specifically applied to wounds, skin, mucous membranes and mucosa-like unkeratinized epithelial tissues of humans and animals.
A plurality of different antibiotic and antiseptic agents are known for the topical treatment of infectious maladies. A decisive disadvantage of antibiotic agents is that the infecting bacteria show primary resistances, and can acquire secondary resistances, against these agents. Further, antibiotics quite often lead to patient sensitivity, especially after prolonged treatment. The use of antiseptics such as povidone iodine, also known as polyvidone iodine or PVP iodine, i.e. the poly(1-vinyl-2-pyrrolidin-2-one)-iodine complex, can inhibit the formation of resistances to antiseptic or antibiotic agents by infecting bacteria. Antiseptic agents are also much more rarely allergenic when used in patients as compared to antibiotics.
In the scientific literature liposomes have quite often been disclosed as drug carriers. A non-exhaustive list comprises the following, more recent publications:
Hoekstra, H. J., Van Baare, J., Dutrieux, R. P.: Evaluation of topical therapy and wound healing. European Burn Association 5th Congress, Brighton, England, 1993 Neuhann, T., Sommer, G.: Erfahrungen mit Jod-Povidon zur Behandlung der Reratokonjunctivitis epidemica. Z. prakt. Augenh. 1 (1980), p. 65; PA1 Pleyer, U., Schmidt, K., Thiel, H. J. (eds.): Liposomes in Ophthalmology and Dermatology. Hippokrates Verlag Stuttgart, 1993; PA1 Prufer, K., Sternberg, B.: Liposomen in der Medizin-Eine aktuelle Bestandsaufnahme. Z. arzt. Fortbildung 88 (1994), pp. 257-256; PA1 Rubas, W., Schreier, H.: Liposomen: Fortschritt in Herstellungs-Technologie und Therapie Pharmazie in unserer Zeit, 6 (1991) pp. 255-270; PA1 Schreier, H., Bouwstra, J.: Liposomes as topical drug carriers: dermal and transdermal drug delivery. (Submitted); and PA1 Shell, J. W.: Ophthalmic drug delivery systems. Surv. Opthalmol. 29 (1984), 117.
Further, the team of Hoekstra et al. in Beverwijk, Netherlands, has reported on animal experiments with silver sulfadiazine, a chemotherapeutic agent, encapsulated in liposomes and applied to experimental wounds. The results appear to show agent enrichment at the wound bottom and reduced silver resorption, compared with customary silver sulfadiazine ointments.
However, although a lot of attention has been paid for quite some time to liposomes as drug carriers, there appears to be no prior art relating to liposomes as carriers of antiseptic or wound healing promoting agents for external applications.